x Preface. confijse the student. Elaborate drawings, of course, ne- cessitated great labour on rny part, as well as considerable co-operation from makers and the editors of engineering journals. Such aid has,in every case been afforded most ungrudgingly, and in many cases has exceeded my most sanguine hopes, both as regards, drawings and* matter. The necessity of well-detailed, modern examples, has always been present to me, and I confidently believe that such have been supplied. In connection with these, I would ask the reader to uriite with me in thanking the following firms and gentlemen who have $o kindly helped :— , Messrs, the Britannia Company, Colchester. „ . George Booth & Co., Halifax. „ Joshua Buckton & Co., Leeds. v/ Mr. John Cochrane, Barrhead, N.'B. 1 Mons. Delamare-Deboutteville, Rouen. Messrs, the East Ferry Road Engineering Works Company, MillwalK The Editors of Engifmriug', London. Messrs. Greenwood & Batley, Leeds. „ Andrew Handyside & Co., Derby. „ Hulse & Co., Manchester. „ B. & S. Massey, Manchester. „ Priestman Bros., Hull „ David Rollo & Sons, Liverpool, „ Samuelson & Co., Banbury, n Selig^ Sonnent|ial & Co., London, „ James Simpson & Co., Pimllox n Smith, Seacock, and Tannctt, Leeds. „ Smith & Coventry, Manchester. •> . „ the Sturtevant Blower Company, Boston, U.S.A.t and London, jj, Tangyes Limited* Birmingham. Mr. Ralph H. Tweddell^ Westminster. ' Sir J. Whitworth & Co,,' Manchester. Mr. Wilson Wof^del!,- of the N.E. Railway.